Autodesk CFD 2023 Black Book

By Gaurav Verma and Matt Weber

The Autodesk CFD 2023 Black Book, is New and updated 3rd edition of our series on Autodesk CFD. The book is targeted for beginners of Autodesk CFD. This book covers the basic equations and terms of Fluid Dynamics theory. The book covers all the major tools of Flow Simulation modules like Fluid Flow, Thermal Fluid Flow, and Electronic Cooling modules. This book can be used as supplement to Fluid Dynamics course if your subject requires the application of Software for solving CFD problems. Some of the salient features of this book are:

 

In-Depth explanation of concepts

Every new topic of this book starts with the explanation of the basic concepts. In this way, the user becomes capable of relating the things with real world.

 

Topics Covered

Every chapter starts with a list of topics being covered in that chapter. In this way, the user can easy find the topic of his/her interest easily.

 

Instruction through illustration

The instructions to perform any action are provided by maximum number of illustrations so that the user can perform the actions discussed in the book easily and effectively. There are about 700 illustrations that make the learning process effective.

 

Tutorial point of view

The book explains the concepts through the tutorial to make the understanding of users firm and long lasting. Practical of the book are based on real world projects.

 

For Faculty

If you are a faculty member, then you can ask for video tutorials on any of the topic, exercise, tutorial, or concept. As faculty, you can register on our website to get electronic desk copies of our latest books, self-assessment, and solution of practical. Faculty resources are available in the Faculty Member page of our website once you login. Note that faculty registration approval is manual and it may take two days for approval before you can access the faculty website.

• Language: English
• Publisher: CADCAMCAE Works
• Release date: Sep 17, 2022
• ISBN: 9798215275870

Gaurav Verma

Gaurav Verma is currently a Full Professor at the Panjab University, Chandigarh, India (Dr. SS Bhatnagar University Institute of Chemical Engineering and Technology, and Adjunct Faculty at the Department of Nanoscience and Nanotechnology). He is a former CV Raman Post-Doctoral fellow from the Department of Chemical Engineering, Massachusetts Institute of Technology (MIT), USA. His research focuses on the areas of applied nanoscience and nanostructured materials.

Book preview

Autodesk_CFD_2023_Book_Cover_BW.jpg

Autodesk CFD 2023 Black Book

(Colored)

By

Gaurav Verma

Matt Weber

(CADCAMCAE Works)

Published by CADCAMCAE WORKS, USA. Copyright © 2022. All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means, or stored in the database or retrieval system without the prior permission of CADCAMCAE WORKS. To get the permissions, contact at [e-mail] or [e-mail]

NOTICE TO THE READER

Publisher does not warrant or guarantee any of the products described in the text or perform any independent analysis in connection with any of the product information contained in the text. Publisher does not assume, and expressly disclaims, any obligation to obtain and include information other than that provided to it by the manufacturer.

The reader is expressly warned to consider and adopt all safety precautions that might be indicated by the activities herein and to avoid all potential hazards. By following the instructions contained herein, the reader willingly assumes all risks in connection with such instructions.

The Publisher makes no representation or warranties of any kind, including but not limited to, the warranties of fitness for a particular purpose or merchantability, nor are any such representations implied with respect to the material set forth herein, and the publisher takes no responsibility with respect to such material. The publisher shall not be liable for any special, consequential, or exemplary damages resulting, in whole or part, from the reader’s use of, or reliance upon, this material.

DEDICATION

To teachers, who make it possible to disseminate knowledge

to enlighten the young and curious minds

of our future generations

To students, who are the future of the world

THANKS

To my friends and colleagues

To my family for their love and support

Training and Consultant Services

At CADCAMCAE WORKS, we provide effective and affordable one to one online training on various software packages in Computer Aided Design(CAD), Computer Aided Manufacturing(CAM), Computer Aided Engineering (CAE), and Computer programming languages(C/C++, Java, .NET, Android, Javascript, HTML and so on). The training is delivered through remote access to your system and voice chat via Internet at any time, any place, and at required pace to individuals, groups, students of colleges/universities, and CAD/CAM/CAE training centers. The main features of this program are:

Training as per your need

Highly experienced Engineers and Technician conduct the classes on the software applications used in the industries. The methodology adopted to teach the software is totally practical based, so that the learner can adapt to the design and development industries in almost no time. The efforts are to make the training process cost effective and time saving while you have the comfort of your time and place, thereby relieving you from the hassles of traveling to training centers or rearranging your time table.

Software Packages on which we provide basic and

advanced training are:

CAD/CAM/CAE: CATIA, Creo Parametric, Creo Direct, SolidWorks, Autodesk Inventor, Solid Edge, UG NX, AutoCAD, AutoCAD LT, EdgeCAM, MasterCAM, SolidCAM, DelCAM, BOBCAM, UG NX Manufacturing, UG Mold Wizard, UG Progressive Die, UG Die Design, SolidWorks Mold, Creo Manufacturing, Creo Expert Machinist, NX Nastran, Hypermesh, SolidWorks Simulation, Autodesk Simulation Mechanical, Creo Simulate, Gambit, ANSYS and many others.

Computer Programming Languages: C++, VB.NET, HTML, Android, Javascript and so on.

Game Designing: Unity.

Civil Engineering: AutoCAD MEP, Revit Structure, Revit Architecture, AutoCAD Map 3D and so on.

We also provide consultant services for design and development on the above mentioned software packages

For more information you can mail us at:

[e-mail] or [e-mail]

Preface

Autodesk® CFD is a software developed by Autodesk Inc. to perform computational dynamic study and thermal simulation on the model. There are various areas where CFD is implemented in Design industry. Some examples of CFD applications are finding: Wind resistance of a car or motorcycle, Pressure drop through a valve, Component temperatures in an electronics enclosure, Comfort of people in a crowded meeting hall, and so on.

The Autodesk CFD 2023 Black Book, is the 3rd edition of our series on Autodesk CFD. The book is targeted for beginners of Autodesk CFD. This book covers the basic equations and terms of Fluid Dynamics theory. The book covers all the major tools of Flow Simulation modules like Fluid Flow, Thermal Fluid Flow, and Electronic Cooling modules. This book can be used as supplement to Fluid Dynamics course if your subject requires the application of Software for solving CFD problems. Some of the salient features of this book are:

In-Depth explanation of concepts

Every new topic of this book starts with the explanation of the basic concepts. In this way, the user becomes capable of relating the things with real world.

Topics Covered

Every chapter starts with a list of topics being covered in that chapter. In this way, the user can easy find the topic of his/her interest easily.

Instruction through illustration

The instructions to perform any action are provided by maximum number of illustrations so that the user can perform the actions discussed in the book easily and effectively. There are about 700 illustrations that make the learning process effective.

Tutorial point of view

The book explains the concepts through the tutorial to make the understanding of users firm and long lasting. Practical of the book are based on real world projects.

For Faculty

If you are a faculty member, then you can ask for video tutorials on any of the topic, exercise, tutorial, or concept. As faculty, you can register on our website to get electronic desk copies of our latest books, self-assessment, and solution of practical. Faculty resources are available in the Faculty Member page of our website (www.cadcamcaeworks.com) once you login. Note that faculty registration approval is manual and it may take two days for approval before you can access the faculty website.

Formatting Conventions Used in the Text

All the key terms like name of button, tool, drop-down etc. are kept bold.

Free Resources

Link to the resources used in this book are provided to the users via email. To get the resources, mail us at [e-mail] or [e-mail] with your contact information. With your contact record with us, you will be provided latest updates and informations regarding various technologies. The format to write us e-mail for resources is as follows:

Subject of E-mail as Application for resources of .............Book.

You can give your information below to get updates on the book.

Name:

Course pursuing/Profession:

Contact Address:

E-mail ID:

For Any query or suggestion

If you have any query or suggestion please let us know by mailing us on [e-mail]. Your valuable constructive suggestions will be incorporated in our books and your name will be addressed in special thanks area of our books.

About Author

Gaurav Verma is a Mechanical Design Engineer with deep knowledge of CAD, CAM and CAE field. He has an experience of more than 10 years on CAD/CAM/CAE packages. He has delivered presentations in Autodesk University Events on AutoCAD Electrical and Autodesk Inventor. He is an active member of Autodesk Knowledge Share Network. He has provided content for Autodesk Design Academy. He is also working as technical consultant for many Indian Government organizations for Skill Development sector. He has authored books on SolidWorks, Mastercam, Creo Parametric, Autodesk Inventor, Autodesk Fusion 360, and many other CAD-CAM-CAE packages. He has developed content for many modular skill courses like Automotive Service Technician, Welding Technician, Lathe Operator, CNC Operator, Telecom Tower Technician, TV Repair Technician, Casting Operator, Maintenance Technician and about 50 more courses. He has his books published in English, Russian, Spanish, and Hindi worldwide.

He has trained many students on mechanical, electrical, and civil areas of CAD-CAM-CAE. He has trained students online as well as offline. He has a small workshop of 20 CNC and VMC machines where he challenges his CAM skills on different Automotive components. He is providing consultant services to more than 15 companies worldwide. You can contact the author directly at [e-mail]

Table of Contents

Training and Consultant Services iv

Preface viii

About Author x

Chapter 1 : Introduction to Autodesk CFD

Introduction of Fluid Mechanics 1-2

Basic Properties of Fluids 1-2

Mass Density, Weight Density, and Specific Gravity 1-2

Viscosity 1-2

Problem on Viscosity 1-3

Types of Fluids 1-4

Thermodynamic Properties of Fluid 1-4

Universal Gas Constant 1-5

Compressibility of Gases 1-5

Vapour Pressure and Cavitation 1-5

Pascal’s Law 1-5

Fluid Dynamics 1-5

Bernoulli’s Incompressible Fluid Equation 1-5

Eulerian and Lagrangian Method of Analysis 1-6

Differential Approach of Fluid Flow Analysis 1-7

Acceleration 1-7

Introduction to CFD 1-7

Conservation of Mass 1-12

Conservation of Momentum 1-12

Conservation of Energy 1-14

Variations of Navier-Strokes Equation 1-15

Time Domain 1-15

Compressibility 1-15

Low and High Reynolds Numbers 1-16

Turbulence 1-17

Steps of Computational Fluid Dynamics 1-19

Creating Mathematical Model 1-19

Discretization of Model 1-19

Analyzing with Numerical Schemes 1-20

Solution 1-20

Visualization (Post-processing) 1-20

Finite Difference Method 1-20

Introduction to Autodesk CFD 1-22

Use of Autodesk CFD 1-23

Applications of Autodesk CFD 1-23

How does CFD works 1-24

Advantages of Autodesk CFD 1-25

Downloading and Installing Autodesk CFD Student Version 1-25

Starting Autodesk CFD 1-27

Start & Learn tab 1-28

Self-Assessment 1-36

Chapter 2 : Model Setup in Autodesk CFD

Introduction 2-2

Model Setup in Autodesk CFD 2-2

Edge Merge 2-2

Small Object 2-4

Void Fill 2-5

Ext. Volume 2-6

Navigation 2-9

ViewCube 2-9

Full Navigation Wheel 2-10

Zoom 2-15

Look At 2-17

Customize Menu 2-17

Context Toolbar 2-18

Self-Assessment 2-24

Chapter 3 : Creating Analysis Model

Introduction 3-2

Applying Materials 3-2

First Method 3-3

Second Method 3-3

Third Method 3-3

Fourth Method 3-4

Scenario Environment 3-6

Material Editor 3-6

Applying Boundary Conditions 3-11

First Method 3-11

Second Method 3-12

Third Method 3-13

Initial Conditions 3-22

Applying Initial Conditions 3-22

Generating Mesh 3-24

Automatic Mesh Generation 3-25

Manual Mesh Generation 3-27

Motion 3-33

Types of Motion 3-33

Self-Assessment 3-43

Chapter 4 : Solving Analysis

Introduction 4-2

Solving Analysis 4-2

Method 1 4-2

Method 2 4-2

Method 3 4-3

Solve dialog box 4-4

Solve Manager 4-18

Job Monitor 4-19

Notifications 4-19

Monitor Point 4-21

Solver Computers 4-22

Selection panel 4-23

Materials panel 4-24

Design Study Tool panel 4-25

Add/Update Design 4-25

Templates 4-26

Flags 4-29

Self Assessment 4-30

Chapter 5 : Analyzing Results

Introduction 5-2

Results Tab 5-2

Results Tasks panel 5-2

Traces 5-19

Iso Volumes 5-35

Review Panel 5-46

Iteration/Step 5-50

Image Panel 5-50

Practical 5-52

Self Assessment 5-56

Chapter 6 : Comparing and Visualization

Introduction 6-2

Decision Center 6-2

Update Panel 6-2

Decision Center Layout 6-3

Save panel 6-5

View tab 6-6

Appearance panel 6-6

View Settings panel 6-13

Window panel 6-15

Chapter 7 : Practical

Introduction 7-2

Practical 1 7-2

Practical 2 7-14

Practical 3 7-36

Chapter 8 : Practical and Practice

Introduction 8-2

Practical 4 8-2

Practical 5 8-10

Practice 1 8-18

Practice 2 8-19

Practice 3 8-21

Chapter 1

Introduction to Autodesk CFD

The major topics covered in this chapter are:

•Introduction to Fluid Mechanics

•Introduction to CFD

•Introduction to Autodesk CFD

•Downloading Autodesk CFD

Introduction of Fluid Mechanics

During the course, you will know various aspects of Autodesk CFD for various practical problems. But, keep in mind that all computer software work on same concept of GIGO which means Garbage In - Garbage Out. So, if you have specified any wrong parameter while defining properties of analysis then you will not get the correct results. This problem demands a good knowledge of Fluid Mechanics so that you are well conversant with the terms of classical fluid mechanics and can relate the results to the theoretical concepts. In this chapter, we will discuss the basics of Fluid Mechanics and we will try to relate them with analysis wherever possible.

Basic Properties of Fluids

There are various basic properties required while performing analysis on fluid. These properties are collected by performing experiments in labs. Most of these properties are available in the form of tables in Steam Tables or Design Data books. These properties are explained next.

Mass Density, Weight Density, and Specific Gravity

•Density or Mass Density is the mass of fluid per unit volume. In SI units, mass is measured in kg and volume is measured in m³. So, mathematically we can say,

Density (or Mass Density)

kg/m³

•If you are asked for weight density then multiply mass by gravity coefficient. Mathematically it can be expressed as:

Weight Density w =

N/m³

•Most of the time, fluid density is available as Specific Gravity. Specific gravity is the ratio of weight density of fluid to weight density of water in case of liquid. In case of gases, it is the ratio of weight density of fluid to weight density of air. Note that weight density of water is 1000 kg/m³ at 4 oC and weight density of air is 1.225 kg/m³ at 15 oC.

Note that as the temperature of liquid rises, its density is reduced and vice-versa. But as the temperature of gas rises, its density is increased and vice-versa.

Viscosity

Viscosity is the coefficient of friction between different layers of fluid. In other terms, it is the shear stress required to produce unit rate of shear strain in one layer of fluid. Mathematically it can be expressed as:

N.s/m² or Pa.s

Where, μ is viscosity, τ is shear stress (or force applied tangentially to the layer of fluid) and (dx/dy) is the shear strain.

As the density of fluid changes with temperature so does the viscosity. The formula for viscosity of fluid at different temperature is given next.

For Liquids,

For Gases,

here, is viscosity at 0 oC

α and β are constants for fluid (for water α is 0.03368 and β is 0.000221)

(for air α is 5.6x10-8 and β is 1.189x10-10)

t is the temperature

Problem on Viscosity

Dynamic viscosity of lubricant oil used between shaft and sleeve is 8 poise. The shaft has a diameter of 0.4 m and rotates at 250 r.p.m. Find out the power lost due to viscosity of fluid if length of sleeve is 100 mm and thickness of oil film is 1.5 mm; refer to below figure.

Solution:

Viscosity μ = 8 poise = 8/10 N.s/m² =0.8 N.s/m²

Tangential velocity of shaft = 5.236 m/s

Using the relation,

where dx is 5.236

and dy is 1.5x10-3

= 2792.53 N/m²

Shear force F = τ x Area

N

Torque (T) = Force x Radius = 350.92 x 0.2 = 70.184 N.m

Power = 2 π.N.T/60 = (2 π x 250 x 70.184)/60=1837.41 W Ans.

Now, you may ask how this problem relates with CFD. As discussed earlier, the viscosity changes with temperature and as fluid flows through pipe or comes in contact with rolling shaft, its temperature rises. In such cases, CFD gives the approximate viscosity and temperature of fluids in the system at different locations. This data later can be used to find solution for other engineering problems.

Types of Fluids

There are mainly 5 types of fluids:

Ideal Fluids: These fluids are incompressible and have no viscosity which means they flow freely without any resistance. This category of fluid is imaginary and used in some cases of calculations.

Real Fluids: These are the fluids found in real world. These fluids have viscosity values as per their nature and can be compressible in some cases.

Newtonian Fluids: Newtonian fluids are those in which shear stress is directly proportional to shear strain. In a specific temperature range, water, gasoline, alcohol etc. can be Newtonian fluids.

Non-Newtonian Fluids: Those fluids in which shear stress is not directly proportional to shear strain. Most of the time Real Fluids fall in this category.

Ideal Plastic Fluids: Those fluids in which shear stress is more than yield value and so fluid deforms plastically. The shear stress in these fluids is directly proportional to shear strain.

Thermodynamic Properties of Fluid

Most of the liquids are not considered as compressible in general applications as their molecules are already bound closely to each other. But, Gas have large gap between their molecules and can be compressed easily relative to liquids. As we pick pressure to compress the gas, other thermodynamic properties also come into play. The relationship between Pressure, Temperature, and specific Volume is given by;

P.V = RT

P = Absolute pressure of a gas in N/m²

V = Specific Volume = 1/ ρ

R = Gas Constant (for Air is 287 J/Kg-K

T = Absolute Temperature

ρ = Density of gas

If the density of gas changes with constant temperature then the process is called Isothermal process and if density changes with no heat transfer then the process is called Adiabatic process.

For Isothermal process, p/ρ = Constant

For Adiabatic process, p/ ρk = Constant

Here, k is Ratio of specific heat of a gas at constant pressure and constant volume (1.4 for air).

Universal Gas Constant

By Pressure, Temperature, volume equation,

p.V = nMRT

Here,

p = Absolute pressure of a gas in N/m²

V = Specific Volume = 1/ ρ

n = Number of moles in a Volume of gas

M = Mass of gas